1. Technical Description
The present disclosure is directed to circular stapling devices and, more particularly, to circular stapling devices that include a knife carrier that is releasably coupled to a knife carrier pusher.
2. Background of Related Art
Conventional circular stapling devices include an elongate body and a shell or reload assembly supported on a distal end of the elongate body. The reload assembly includes a staple cartridge that supports a plurality of staples, a pusher that is movable in relation to the staple cartridge to eject staples from the staple cartridge, a knife, and a knife carrier that supports the knife and is movable through the staple cartridge to core tissue. The surgical stapling device also includes a pusher drive member and a knife carrier pusher that are supported within the elongate body. The pusher drive member is engaged with the staple pusher and is movable to move the staple pusher to eject staples from the staple cartridge. Similarly, the knife carrier pusher is engaged with the knife carrier and is movable to effect movement of the knife carrier to core tissue. In some circular stapling devices, the knife carrier pusher and the knife carrier are separable to facilitate separation of the reload assembly from the elongate body of the surgical stapling device.
In current designs, a back angle is formed on the knife carrier pusher to facilitate separation of the knife carrier pusher from the knife carrier. In these designs, if the back angle selected is too small, the knife carrier can be damaged upon removal of the reload from the elongate body, and if the back angle selected is too large, disengagement of the knife carrier pusher from the knife carrier can occur prematurely such that full retraction of the knife is not achieved.
A need exists in the stapling arts for a simple but reliable mechanism to effect engagement and disengagement of the knife carrier and the knife carrier pusher at the appropriate times.